inadequate if any non-sportsman
featherweights with overhead
weapons competed, but that’s not
an issue since the class is currently
made up of mostly spinners and
wedges. Everything was secured
together with 10-32 screws for the
metal pieces, and 10-24 and
1/4”- 20 for the UHMW.

The first version of Shaka used
unhardened 4130 steel welded to a
pair of Home Depot hinges in an
attempt to counter wedges. The
hinges were ripped in half on the
first spinner hit and the steel itself
bent horribly. This time, we welded
a pair of single piece anti-wedge
skids out of some 4130. Although
far more durable and effective, they
were rather heavy at around seven
ounces each. When fighting
horizontal spinners and other bots
that the skids would be useless
against, we switched out the steel

PHOTO 4. Shaka’s aluminum weapon rails
after being water jet cut by Team Whyachi.

skids for a UHMW pair and some
ablative . 5” thick UHMW front
armor that had been fabricated out
of the old Shaka’s chassis.

I had originally intended to
power the entire robot off of 24V
of 3,300 mAh NiMH batteries. As
the skids were added to the design,
I began to see that it wouldn’t be
able to make weight with those
batteries. I also wasn’t sure if the
capacity would be sufficient, taking
into account the massive amp
draw of the Dewalts and the large
Axi brushless.

weight check and discovered that it
was a staggering 2. 5 pounds
overweight. The first place I looked
for extra weight was in all of the
aluminum pieces. I began by cutting
down the Dewalt pillow blocks to
nearly half their original weight,
and then milled down the corners
of the weapon-bearing blocks and
pocketed the front aluminum 1/8”
deep. I also slotted out the large
inner aluminum frame rail. After
doing all this, the bot still weighed
30. 5 lbs, but the last eight ounces
were eventually removed by
shortening every wire and taking an
angle grinder to the inside of the
steel side armor. After one and a
half all nighters and two 24 packs
of Dr. Pepper, the robot was
finished four hours before our
plane was scheduled to take off.

After looking at several other
options, I settled for a 5 Ah 20/30C
6s ( 22.2V) LiPoly from United
Hobbies (www.unitedhobbies.
com). Though the quality isn’t as
great as some equivalent brand
name batteries (such as Thunder-Power and Polyquest), the
difference in price was huge ($400).
The only problem I had with it was
that the 20C continuous discharge
rate didn’t seem to be enough.
The battery has since been replaced
with an equivalent 30C continuous
model.

In the end, Shaka went 2-1 at
RoboGames, not including a forfeit
to our other featherweight, Pinball.
In truth though, it only had one real
fight — a one hit victory over the
gas powered horizontal spinner,
Chainzilla. Its other win and only
loss were both from the Brazilian
full body spinner, UFO. Before the
first of these fights (Shaka’s loss),
I was messing around with one of
the Dewalt gearboxes and I forgot
to actually screw it back into the
mount. Shaka was able to move for
the first second of the match, and

PHOTO 8. A completed Shaka gets
ready to fight UFO for a second time at

RoboGames 2009.

After the robot was completed,
we threw it on the scale for a quick

PHOTO 7. The nearly finished robot, still
during the weight reduction process.